Passivity test of Mueller matrices in the presence of additive Gaussian noise.

It is possible to introduce tolerancing with the realizability test of Givens and Kostinski [J. Mod. Opt.40, 471 (1993)] with a minor modification: it suffices to add a special matrix to [G][M](T)[G][M]. Consequently, it is possible to check experimental Mueller matrices with a more flexible tool. Application to the emblematic case of the Mueller images of the free space shows that more than 99% of the pixels are in fact physical, while only 2% initially passed the test.

Directional effects consideration to improve out-doors emissivity retrieval in the 3-13 mum domain.

This work analyses and solves for issues encountered when retrieving surface emissivity in LWIR (750 to 1250 cm(-1)) and MWIR (2000 to 3500 cm(-1)) bands under outdoor conditions. The Spectral Smoothness method, which takes advantage of high spectral resolution measurements to solve for temperature emissivity separation, and which has already proven its efficiency in the LWIR domain, was applied in an experimental campaign to assess its ability to operate both in the LWIR and MWIR domains. In the MWIR band, directional behaviour of surface emissivity is shown to be a source of systematic errors in the retrieved emissivity and a new method, called SmaC (SMoothness And Continuity), corrects for this error by providing quantitative estimates on the deviation of the surface from Lambertian behavior.